Dump salmon into bowl. Pick out as many hard pieces of round bone as possible.(bone is edible i prefer them gone!) add egg, crackers. Mix well with hands. Heat up fry pan with oil. Fry patties about 10 minutes on each side. Meanwhile in small saucepan melt butter. Add flour to make a roux and slowly stir in milk and salt. Cook on low until thickened. Serve sauce over patties.